In late years, there have been made various proposals regarding a walking assist device using robotic technologies to assist an elderly person in going out or carrying articles such as baggage or goods. These proposals include a walking assist device constructed by incorporating a motor and a controller into a conventional hand cart or walking frame for an elderly person. For example, a walking assist device designed for use by an elderly person whose muscles has weaken is configured such that, in a given situation, braking is automatically activated by control of a controller, without a need for a user to manipulate a hand brake to activate braking. As above, it has been expected to realize stabilization of walking using a walking assist device.
A walking aid described in the Patent Document 1 (JP 2898969B) is configured to be capable of setting movement characteristics (speed, resistance, aid gain, and turning gain) of the walking aid arbitrarily and independently, with respect to each of a plurality of modes of movement of a target pedestrian or user to be aided, including forward movement, backward movement and turning, i.e., according to each situation of the target user. Therefore, this walking aid makes it possible to ensure safe walking during forward movement, backward movement or turning of a target user.
On the other hand, a power-assisted transport trolley described in the Patent Document 2 (JP 3032698B) comprises a trolley body provided with: drive wheels; a driving section for driving the drive wheels; and a manipulation member to be manipulated by a user. The transport trolley further comprises: an external force detection means to detect respective force components in a propulsion direction and in a steering direction, from an external force applied from the user to the manipulation member; and a control means to cause a driving source for the drive wheels to generate torques according to the propulsion-directional force and the steering-directional force.
The drive wheels comprises a pair of right and left wheels capable of being driven independently of each other. The right and left wheels function as traveling drive wheels, and also function as steering drive wheels when they are driven in a differential manner. These drive wheels are configured to be driven to generate two assist forces corresponding, respectively, to the propulsion-directional force and the steering-directional force each detected by the external force detection means.
The transport trolley described in the Patent Document 2 is also configured to perform correction of the assist force and addition of viscous drag, according to a traveling speed, a loaded weight and an inclination angle. For example, this transport trolley is configured to be controlled such that a force capable of counterbalancing a force urging the trolley body to move downwardly along an inclination of a downward slope is generated as the assist force.